The present invention relates to a warming device utilizing heat generation accompanying oxidation of an oxidizable metal with oxygen in air.
Known techniques pertinent to warming devices utilizing heat generation accompanying oxidation of an oxidizable metal powder with air oxygen include the warming tool described in JP-A-2003-332.
The warming tool disclosed comprises a cap-shaped base sheet which is put on a head and a plurality of heat generating elements attached to the base sheet, the heat generating elements each comprising an air permeable flat bag containing heat generating powder.
Because the heat generating elements used in this warming tool are thick, a thinner warming device has been desired. Because the heat generating elements lose flexibility as the heat generating powder becomes harder, a warming device having excellent in flexibility and thereby providing a good fit has been desired. Furthermore, since the thick heat generating elements being attached to the base sheet limit the freedom of design, a warming device having broader applications has been demanded.